--- oup/releases/0.34a/Tools/TxmpReplace.pas	2007/05/26 21:12:13	200
+++ oup/releases/0.34a/Tools/TxmpReplace.pas	2007/05/26 21:38:25	203
@@ -102,6 +102,9 @@ var
   mem: TMemoryStream;
   new_storetype: Byte;
   formatinfo: TImageFormatInfo;
+  i: Integer;
+const
+  powers: array[0..8] of Integer = (1, 2, 4, 8, 16, 32, 64, 128, 256);
 begin
   if filelist.ItemIndex >= 0 then
   begin
@@ -111,6 +114,28 @@ begin
     else
       ConManager.Connection[ConnectionID].LoadDatFilePart(fileid, $9C, 4, @old_rawaddr);
 
+    if (OniImage_New.Width[1] > 256) or (OniImage_New.Height[1] > 256) then
+    begin
+      ShowMessage('Widht and height have to be smaller than or equal to 256.');
+      Exit;
+    end;
+    for i := 0 to High(powers) do
+      if OniImage_New.Width[1] = powers[i] then
+        Break;
+    if i = Length(powers) then
+    begin
+      ShowMessage('Width has to be a power of 2 (1, 2, 4, 8, 16 ...)');
+      Exit;
+    end;
+    for i := 0 to High(powers) do
+      if OniImage_New.Height[1] = powers[i] then
+        Break;
+    if i = Length(powers) then
+    begin
+      ShowMessage('Height has to be a power of 2 (1, 2, 4, 8, 16 ...)');
+      Exit;
+    end;
+
     if (OniImage_Old.Width[1] <> OniImage_New.Width[1]) or
       (OniImage_Old.Height[1] <> OniImage_New.Height[1]) then
     begin